School of Medicine, Koç University, Istanbul 34450, Turkey; Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, United Kingdom.
School of Medicine, Koç University, Istanbul 34450, Turkey.
Clin Neurophysiol. 2020 Dec;131(12):2875-2886. doi: 10.1016/j.clinph.2020.09.021. Epub 2020 Oct 16.
Amyotrophic lateral sclerosis (ALS) disrupts motoneurons that control movement and some vital functions, however, exact details of the neuronal circuits involved in ALS have yet to be fully endorsed. To contribute to our understanding of the responsible neuronal circuits, we aimed to investigate the spinal recurrent inhibition (RI) and post-activation depression (P-AD) in ALS patients.
In two groups of ALS patients, i.e. lumbar-affected (clinical signs in leg muscles) and nonlumbar-affected (clinical signs in arms or bulbar region but not in the legs), RI and P-AD on the soleus muscle were investigated using single motor units and amplitude changes of H-reflex in surface electromyography, respectively. The data were compared with healthy subjects.
Compared to controls, P-AD of H-reflex was reduced severely in lumbar-affected patients and reduced to a certain degree in nonlumbar-affected patients. Similarly, a significant reduction in the duration of RI on firing motoneurons was found in lumbar-affected patients (11.5 ± 2.6 ms) but not in nonlumbar-affected patients (29.7 ± 12.4 ms, P < 0.0001) compared to controls (30.8 ± 7.2 ms, P < 0.0001).
The current study revealed that spinal inhibitory circuits are impaired in ALS.
These findings may provide insight for proposing new therapeutic approaches and following disease progression in humans.
肌萎缩侧索硬化症（ALS）会破坏控制运动和一些重要功能的运动神经元，但涉及 ALS 的神经元回路的确切细节尚未得到充分证实。为了帮助我们了解负责的神经元回路，我们旨在研究 ALS 患者的脊髓回返抑制（RI）和后激活抑制（P-AD）。
在两组 ALS 患者中，即腰段受累（腿部肌肉的临床体征）和非腰段受累（手臂或延髓区域的临床体征，但腿部没有），分别使用单运动单位和表面肌电图中 H 反射幅度变化研究了比目鱼肌的 RI 和 P-AD。将数据与健康受试者进行比较。
与对照组相比，腰段受累患者的 H 反射 P-AD 严重降低，而非腰段受累患者的 P-AD 降低到一定程度。同样，在腰段受累患者中（11.5±2.6ms），但在非腰段受累患者中（29.7±12.4ms，P<0.0001），与对照组（30.8±7.2ms，P<0.0001）相比，对运动神经元放电的 RI 持续时间显著缩短。
本研究表明，脊髓抑制回路在 ALS 中受损。
这些发现可能为提出新的治疗方法和在人类中跟踪疾病进展提供了思路。
